Flotation of quartz and other acidic minerals



Patented, Jan. 5, 1943 FLOTATION 0F QUARTZ AND OTHER Aomrc MINERALS Stuart A. Falconer, Old Greenwich, and Stephen E. Erickson, Springdale, Conn., asslgnors to American Cyanamid Company, New York, N. Y., a corporation of Maine No Drawing. Application April 27, 1940, Serial No. 331,930

6 Claims.

This invention relates to the beneficiation of ore materials by froth flotation and more particularly to a method of improving the promoting power of the so-called cationic-type reagents used for floating quartz or silicate minerals.

An important advancement in ore beneflciation processes in recent years has been the development of a class of flotation reagents which act as promoters or collectors for acidic ore material such as quartz or silicate minerals. These promoters have resulted in a more economical and eflicient method of recovering the ore values from a number of ore materials and particularly in connection with froth flotation processes of separating silica. or silicate minerals, such as mica, from the non-metallic ores, limestone, barytes, ilmenite, calcite and the like and especially phosphate minerals. There are, however, many disadvantages which accompany the use of cationic reagents in froth flotation processes. For example, it has been found that the .presence of slimes very greatly reduces the promoting action of these silica promoters. This problem was appreciated and various processes of silica flotation involving a very complete desliming of the flotation feed prior to flotation have been found to produce improved results. Although these complete desliming processes have resulted in the solution of some of the conditions which interfere with the silica flotation, it is still desirable that the promoting or collecting power of such reagents be improved.

According to the present invention it has been discovered that the promoting power of cationic type reagents is increased by mixing the reagents necessary for the flotation operation with the water which is subsequently used to dilute the ore to the pulp density desired for flotation. The reason why the addition of the reagents to the dilution waters seems to increase promoting power of the cationic-type reagent used for floating quartz or silicate minerals has not been determined and the present invention is not dependent upon any theory of explanation thereof.

In carrying out the present invention the entire quantity of the positive ion type reagent required for flotation of the silicate minerals is mixed with the water that is later used to dilute the flotation feed to the desired pulp density for carrying out the actual'flotation. In the prior methods of floating quartz 01' silicate minerals the flotation feed is first diluted to the desired pulp density and the reagents added directly to the ore pulp in the flotation fed in varying quantities.

cell either the entire quantity at once or stage- Sometimes the reagents are fed into the diluted ore pulp in the form of emulsionswhen the reagents used are water insoluble. In no case, however, has it been previously known that the reagents of either the insoluble or soluble type of silica promoters, if mixed with the dilution water, would increase the promoting power of the' reagents.

It is an advantage of our invention that it is somewhat flexible and may be successfully combined with known silica flotation procedures. For example, the process may be combined with a process in which the major portion of the silica promoter is mixed with the dilution water and a minimum portion of the same or a different silica promoter added directly to the diluted ore pulp in the usual manner.

It is also an advantage of the present invention that our'improved process can be used in connection with the various improvements which have been developed in connection with the complete desliming of silicate-containing minerals to effect even a greater saving in reagent cost andv improved recoveries.

While the present invention is not limited to any particular silica flotation reagent and these reagents are generally useful, there are differ- Exmm! 1 The following tests were run on a sample of deslimed phosphate ore flotation feed from Florida. 4

Test 1 In this test a GOO-gram charge of phosphate ore was transferred to a Fagergren flotation machine and diluted to 22% solidswith water.

A total of 0.72 pound of dodecyl amine per ton of ore was then added and conditioned with the ore pulp for 30 seconds. Air was then admitted to the machine and the resulting quartz concentrate froth was skimmed ofl for 3 minutes.

The concentrate recovered in this test weighed 100.8 grams and assayed 82.20% insoluble.

Test 2 In this test the equivalentof 0.5 pound of dodecyl amine per ton of ore was mixed with the required amount of water b stirring for 10 seconds. The mixture of water and reagent was placed in a Fagergren flotation machine. A 600- gram charge of the prosphate ore was then added to aqueous mixture in the flotation machine. No mixing time was allowed as air was admitted immediately to the machine and the resulting quartz concentrate was skimmed off.

The concentrate recovered in this test weighed 173.3 grams and assayed approximately the same as in Test 1.

Test 3 This test was conducted in the same manner as Test 2 except that the 0.5 pound of dodecyl amine per ton of ore was mixed with the water for 1 minutes before the GOO-gram charge of phosphate ore was added.

In this test the concentrate recovered weighed 185.3 grams and assayed approximately the same as in the previous tests.

Test 4 This test was the same as Tests 2 and 3 except that the dodecyl amine was mixed with the water for 5 minutes before the 600-gram charge of phosphate ore was added.

In this test the weight of concentrate recovered was increased to 186.2 grams.

In the Tests 2, 3, and 4, when the silica promoter was added to the water which was later used to dilute the flotation feed the recoveries wererespectively about 72, 85, and 86% higher than in Test 1 when the silica promoter was added directly to the diluted ore pulp. It is to be noted also that in Test 1, 0.72 pound of reagent per ton of ore was used as contrasted to Tests 2, 3, and 4 in which only 0.5 pound of re agent per ton of ore was used.

4 EXAMPLE 2 The following tests were conducted on an ore sample from a feldspar operation in the southeastern United States. This ore contained quartz, feldspar and a small amount of mica.

The ore charge used in these tests had been ground dry and then screened on a 48-mesh screen. Flotation tests were conducted on the -48 mesh screen.

Test 1 In this test a charge of the ore was placed in a Fagergren flotation machine and diluted to 22% of solids with water.

3.8 pounds of 48% hydrogen fluoride solution and 0.56 pound of dodecyl amine hydrochloride were then added and conditioned with the ore pulp for 15 seconds.

Air was then admitted to the machine and the resulting feldspar concentrate was skimmed off for 4 minutes.

The results of this test are given below:

In this test a charge of the ore was placed in the flotation'machine and diluted with water. 3.8 pounds of 48% hydrogen fluoride solution and 0.56 pound of dodecyl amine hydrochloride were.

then added.

Air was admitted to the machine immediately and the resulting feldspar concentrate was skimmed off. No conditioning period before flotation was used in this test.

The resultsobtained follow:

Product Weight Alg0| Percent Percent Percent Concentrate 60. 39 18. 61. 0! Tailing 49.61 12. 24 as 93 Feed 100. 00 15. 60 100. 00

Test 3 Dist. Product Weight A1 0; A110.

Percent Percent Percent Concentrate 62. 2s 18. 78 73. 99 Tailing 37. 72 10. 90 26. ()1

Feed 100.00 15:81 100.00

In the foregoing examples typical amine flotation promoter is employed. The invention, however, is not limited to any particular cation active or positive type reagent and the improved results are obtained when, either all or part of the promoters employed in the examples are replaced by any of the promoters ordinarily employed for silica flotation, such as the aliphatic amines and their halogen and acid salts, quaternary ammonium componds and their salts, pyridinium compounds and their salts, quinolinium compounds and their salts, sulfonium compounds and their salts, phosphonium compounds and their salts, the reaction product of polyalkylene polyamines with fatty acids described in the Erickson, Christmann, and Jayne application Serial No. 326,952, filed March 30, 1940, the fatty acid esters of sulfonic acid salts of amino alcohols described in the Jayne and Day application Serial No. 325,394, filed March 22, 1940, or any compounds employed as silica promoters which owe their effectiveness to positively charged portions of their molecules.

What we claim is:

1. A method of beneflciating ore materials by froth flotation of an acidic mineral concentrate therefrom which comprises the steps of adding at least a major portion of a cationic type pro-- motor necessary for the flotation operation to the quantity of water required tp'ldilute the flotation feed to the desired pulp density, said promoter being one which selectively floats the acidic mineral, agitating and aerating the resultant water-promoter mixture, and adding the flotation feed to said mixture during the agitation and aeration.

2. A method of beneficiating non-metallic ore materials by froth flotation of a silica concentrate therefrom by means of a cationic type promoter which selectively floats the silica which comprises mixing substantially all the silica promoter necessary for the flotation operation with the amount of water required to dilute the flotation feed to the desired pulp density, agitating and aerating the resultant water-promoter mixture, and adding the flotation feed to said mixture during the agitation and aeration.

3. A method of beneflciating phosphate ore materials by froth flotation of a silica concentrate therefrom by means of a promoter which selectivelyfloats the silica which comprises mixing at least a major portion of the silica promoter necessary for the flotation operation with the amount of water required to dilute the flotation feed to the desired pulp density, agitating and aerating the resultant water-promoter mixture, and adding the flotation feed to said mixture during the agitation and aeration.

4. A method of beneficiating feldspar ore materials by froth flotation of a silica concentrate therefrom by means of a promoter which selectively floats the silica which comprises mixing at least a major portion of the silica promoter necessary for the flotation operation with the amount of water required to dilute the flotation feed to the desired pulp density, agitating and aerating the resultant water-promoter mixture, and adding the flotation feed to said mixture during the agitation and aeration.

5. A method of beneflciating phosphate ore materials by froth flotation of a silica concentrate therefrom by means of a long chain aliphatic amine silica promoter which comprises mixing substantially all the silica promoter necessary for the flotation operation with the amount of water required to dilute the flotation feed to the desired pulp density, agitating and aerating the resultant water-promoter mixture, and adding the flotation feed to saidmixture during the agitation and aeration.

6. A method of beneflciating feldspar ore materials by froth flotation of a silica concentrate therefrom by means of a long chain aliphatic amine silica promoter which comprisesmixing substantially all the silica promoter necessary for the flotation operation with the amount of I water required to dilute the flotation feed to the desired pulp density, agitating and aerating the resultant water-promoter mixture, and adding the flotation feed to said mixture during the agitation and aeration.

STUART A. FALCONER.

STEPHEN E. ERICKSON. 

